Definition of Upper leg

Upper leg: The upper leg is the superior (top) segment of the leg: the part above the knee.

As compared to the lower leg which boasts two bones (the tibia and the fibula), the upper leg has only one bone: the femur but a very large bone it is, the largest in the human body, extending by necessity from the hip to the knee.

The word "femur" is the Latin word for thigh and the femur is familiarly known as the thigh bone.